


Under Your Spell

by Arborescent



Category: Undertale (Video Game)
Genre: Grillby is a priest, I'm so rusty oh gosh, M/M, Possession!Au inspired by a friend, Smut in the future I promise, be gentle w me, don't judge okay, literally I have not written anything in years
Language: English
Status: In-Progress
Published: 2015-12-05
Updated: 2015-12-04
Packaged: 2018-05-05 00:46:45
Rating: Not Rated
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,241
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5354534
Author URL: https://archiveofourown.org/users/Arborescent/pseuds/Arborescent
Summary: <blockquote class="userstuff">
              <p>The years of meticulous training and every warning he'd been given were useless when it came to the smug giant standing before him.</p>
<p>Lord help him.</p>
<p> </p>
<p>mmmsammiches on tumblr mentioned the idea of a demon!Gaster and it slowly morphed into Grillster because what else would happen lmao</p>
            </blockquote>





	Under Your Spell

“As you can see, Father, it’s only gotten worse since we spoke on the phone,” the woman tells him in a hushed voice, glancing nervously at the figure tied to the chair. The smaller monster’s head hung limply, skin ashen to an almost unnatural gray, silent and unmoving despite the two speaking in front of it. Grillby looked him over just as quietly, clutching his briefcase tightly. He’d come prepared for the worst case scenario, a full possession, but it looked like he had managed to arrive while it was still in the oppression stage.

That might make things easier.

He ushered the woman out of the room so he could begin and turned attention back to the young monster, small and still clad in a striped sweater. Grillby set his briefcase on a nearby table and opened it, sight falling over the tools, tracing a gloved hand over polished wooden crucifixes, small ornate glass bottles of holy water and finally rested on his worn bible. He was running his hand down the cover when an inhuman gurgling broke the eerie quiet of the room. He turned sharply, meeting two empty white eyes that pierced through his body and soul. He shivered and the small monster took notice, smiling at the reaction, black ooze dripping out of its mouth. It gurgled again, trying to form words, but blew inky bubbles and choked on the slime instead as it leaned towards the priest, eyes wide. Grillby reached back to the briefcase, sliding out his small bible while his other hand traced out the familiar cross in front of him.

“In the name of Jesus Christ, our God and Lord,” he began, ignoring how the smile on the monster grew slightly menacing, “strengthened by the intercession of the Immaculate Virgin Mary, Mother of God, of Blessed Mich-” the small monster shrieked suddenly, struggling violently as Grillby continued, attempting to raise his voice to drown out the noise. His hand moved to retrieve a crucifix and the child screamed more, spitting the black slime viciously. Grillby did not falter as his fingers wrapped around the cross, gripping it until his hand ached when silence filled the room again. A pressure replaced the once shrill screeches, almost taking on a static buzzing he wasn't sure he actually heard. He looked at the child whose mouth hung open, no longer gushing ooze and void of any expression as he held up the crucifix.  
“Behold the Cross of the Lord, flee bands of enemies. The Lion of the tribe of Juda, the offspring of David, hath conquered,” he started, unfaltering when the child started murmuring words.

“May Thy mercy, Lord, descend upon us. As great as our hope in Thee.” he spoke softly, ignoring as the light hanging from the ceiling flickered quickly. His voice halted, though, when it hummed loudly, brightening intensely before burning out with a loud pop. The sudden darkness was unnerving, but Grillby’s own light was enough to fill the room, albeit dimly. It was a different kind of darkness than he’d ever experienced, one that loomed unnaturally close to his body, one his fire could barely cut through, and he felt fear crawl up his spine. He looked back at the child for a sign but their eyes were locked firmly on something behind him. Grillby turned and was met with the same unforgiving shadows that filled the rest of the room but he froze at the small voice in front of him.

“Can you imagine how scary a world that looks the same would be,” it began, “One where you don’t exist in it, and it functions perfectly without you?” the small monster whispers, eyes still trained on the spot just over Grillby’s shoulder. Their head lolls slightly to the side and Grillby takes a step closer, apprehensive and curious.

“What are you talking about?” he finally asks, crouching to head level. The monster locks eyes with him, expressionless.  
“You should forget about me.” is the hollow response he receives before blank white eyes return back to void behind him. Grillby’s flame flickers a little, confused but determined nonetheless to finish what he started.  
“Whatever you are,” he mutters, hints of confrontation seeping into his words, “I will send you back to hell where you belong. I will save this child from such an abominable creature of hell.” He raised the cross once more, and looked back down to his bible, mustering up all the strength he could as the air sharply chilled in response to the challenge. 

“We drive you from us, “ he began, voice as strong as he could manage and the static noise returned, full force and right in his ears. He swore he heard words in it, smothered in audio fuzz and difficult to make out. He tried to latch onto the sounds and decipher them when the little monster’s eyes widened, mouth hanging open in anticipation.  
“We drive you from us,” Grillby boomed, the fire on his head matching the ferocity of his words as the shadow crept unknowingly closer to him, “whoever you may be!”  
Unseen hands shot out from the looming shadow, grabbing onto Grillby’s forearms and sharply pulling them back behind him without warning. His bible and crucifix clattered onto the ground and he felt himself being forced backwards towards the table, before an immense pressure pinned his arms to the top. His briefcase was knocked unceremoniously to the floor, glass shattering and spilling contents all over. He hissed at the impact, head whipping around to find the source of whatever kept him locked to the table, back arched and aching as he struggled to pull himself up.  
The priest frantically looked around the empty room once more when it struck him that he was alone. The small gray form he had been trying to save had vanished from existence itself it seemed, and the life all but drained from him upon this realization. The sudden breathe against his ear did not help in calming the fear that now trickled down his spine, and the ungodly darkness that had filled the room suddenly made sense to him. This was much bigger than he had imagined. Swallowing thickly, Grillby willed himself to be strong, hands clenched into fists.  
“In the Name and by the power of Our Lord Jesus Christ, may you be snatched away and driven from the Church of God.” It was shaky, forced and the breathing next to his face became a low scratchy chuckle at his attempt, squeezing his forearms tighter.

"I heard what you said earlier." It was low, like a poor reception from the radio, filled with static and crackling, but it was dripping in self satisfaction, smug and too close. Grillby tried to lean away when he felt a thick wet tendril slithering up his back, wrapping loosely around his torso before it reached up to press itself against his cheek. He froze, panicked at the sudden contact.. 

“A͍n abominable creature of hell....Right, Father?" the voice rumbled out another laugh and the slimy appendage pushed sharply against his cheek, forcing him to turn his head. Grillby gasped, a face now leering inches from his, small white pinpricks set in unnervingly deep empty sockets locked onto him.The priest willed himself to look away, breaths shallow and sporadic as the eyes in front of him narrowed dangerously.

"It's rude to gossip about someone who's listening, you know."


End file.
